Numerous detection and analysis methods for determining physiological parameters in samples of bodily fluid such as blood, plasma, serum or urine or in other biological samples are nowadays carried out in an automated manner in corresponding analysis apparatus.
Current analysis apparatus are able to carry out many different kinds of detection reactions and analyses with a large number of samples. Analysis apparatus of the kind presently used in clinical laboratories or in blood banks usually comprise an area for the delivery of sample vessels that contain the primary samples to be analyzed. To feed the sample vessels into the analysis apparatus, a transport system is usually provided which firstly transports the sample vessels to a sample identification device, which detects sample-specific information applied to a sample vessel and transmits said information to a storage unit. Thereafter, the sample vessels are transported to a sampling station. With the aid of a sample pipetting device, at least one aliquot of the sample liquid is removed there from a sample vessel and is transferred to a reaction vessel.
The reaction vessels are generally in the form of disposable cuvettes which are stored in a cuvette container in the analysis apparatus and which are transferred automatically from the storage container to defined receiving positions. The reagents needed for providing different types of test-specific reaction mixtures are located in reagent containers, which are stored in a reagent station. The reagent containers are delivered to the analysis apparatus either automatically or manually.
Measurement systems which are based on photometric (e.g. turbidimetric, nephelometric, fluorometric or luminometric) or radiometric measurement principles are particularly common. These methods permit the qualitative and quantitative detection of analytes in liquid samples, without having to provide additional separating steps. Clinically relevant parameters, such as the concentration or the activity of an analyte, are often determined by virtue of an aliquot of a bodily fluid of a patient being mixed, simultaneously or in succession, with one or more test reagents in the reaction vessel, as a result of which a biochemical reaction is started which brings about a measurable change in an optical property of the test mixture.
The measurement result is in turn forwarded from the measurement system to a storage unit and evaluated. Subsequently, the analysis apparatus supplies sample-specific measurement values to a user via an output medium, e.g. a monitor, a printer or a network connection.
The reaction vessels are often delivered to the various measurement systems on a circular transport wheel. A wheel of this kind is usually arranged with a perpendicular central axis in the automatic analysis apparatus and has, along its outer circumference, a large number of holders for reaction vessels. The reaction vessels are usually cylindrical and are oriented with their central axis parallel to that of the wheel. In this way, the reaction vessels can be inserted from above into the holders, moved to another location by means of rotation of the wheel and once again removed there.
Depending on how long the reaction vessels remain in the transport wheel, it may be necessary to protect the content of the reaction vessels from evaporation and external influences, e.g. dust or light. A lid is normally used for this purpose. However, in automated processing in an analysis apparatus, it is necessary that this lid can be automatically opened at any time and closed again, in order to add reagents or to remove sample liquid. The actuation of the lid should as far as possible be effected with already existing movements in the apparatus, such that no additional technical outlay is needed in respect of position determination and the actuation of the lid.